British Submarine "Sidon" 1955

Medium Range Patrol

N50 32.778 W2 38.400

Class and type:S-class submarine
  • 814-872 tons surfaced
  • 990 tons submerged
Length:217 ft (66 m)
Beam:23 ft 6 in (7.16 m)
Draught:11 ft (3.4 m)
  • 14.75 knots (27 km/h) surfaced
  • 8 knots (15 km/h) submerged
Complement:48 officers and men

HMS Sidon was a submarine of the Royal Navy, launched in September 1944, one of the third group of S class built by Cammell Laird & Co Limited, Birkenhead, named after the naval bombardment of Sidon in 1840. An explosion caused by a faulty torpedo sank her in Portland Harbour with the loss of 13 lives.

One week later the wreck was raised and towed into a causeway on Chesil Beach. The bodies of the 13 casualties were removed and buried with full honours in the Portland Royal Naval Cemetery overlooking the harbour.

A court of inquiry cleared anyone aboard Sidon for the loss of the boat. The direct cause of the accident was determined to have been malfunctioning of the “Fancy” torpedo. A torpedo being readied for the morning test shot had begun a “hot-run” – its engine had started while it was still inside the submarine and was over-speeding, creating very high pressures in its fuel system. The “Fancy” torpedo used high test peroxide (HTP) as an oxidizer. When an oxidizer line burst, HTP sprayed onto the copper fittings inside the torpedo, decomposing into oxygen and steam. The torpedo’s warhead did not detonate, but its hull burst violently, rupturing the torpedo tube and causing the flooding that destroyed the boat. The torpedo programme was terminated and the torpedoes taken out of use by 1959.

Sidon was refloated, then sunk to act as an ASDIC target on 14 June 1957.

On the 50th Anniversary of the Sidon accident, 16 June 2005, the Dorset Branch of the Submariners Association erected a Memorial Stone to those who died. This is situated adjacent to the Portland Cenotaph at Portland, opposite the Portland Heights Hotel. A number of survivors and relatives of those who died in the accident attended the ceremony.

Sidon’s wreck was purchased from the Ministry of Defence by the company Deepquest Sub Sea in 2000. In 2002 the company announced that it intended to raise the wreck. This had not occurred as of 2003

Images -Emma Harris